The present disclosure relates to an image reading device and an image forming apparatus equipped with the image reading device.
In general, it is known that, in an image reading device, a CIS (contact image sensor) is employed as an image sensor for reading an image of a document sheet. In order to improve the speed of reading an image, a CIS module having a plurality of channels is employed in some cases.
The CIS module having a plurality of channels includes a light emitting portion and a plurality of single-channel light amount sensors. The light emitting portion emits light to a main scanning region extending along one straight line. The plurality of single-channel light amount sensors are disposed in series along the main scanning region. Each of the single-channel light amount sensors receives light from its corresponding one of partial scanning regions which are each a part of the main scanning region, and outputs detection data of the amount of the received light. The respective single-channel light amount sensors perform the receiving of the light and the outputting of the detection data in parallel.
It is also known that: the plurality of CISs are disposed along the main scanning direction with their respective end portions overlapping each other, and image data outputted by each CIS is corrected on the basis of a detection result of variation of the amount of light from the light emitting portion in the CIS. In this case, on the basis of data read from a white reference plate opposed to an end portion of each CIS, variation of the amount of light from the light emitting portion is detected.